There’s little in the flat suburbs of Sacramento, California that I ever would have associated with epic tragedy before I flew there one warm afternoon to talk with a group of Mayan Kanjobal Indians from Guatemala, survivors of one of the hemisphere’s most terrible genocides.

It was 1991, and along with other lawyers at the Center for Constitutional Rights, I was following up on information about the massacres in Guatemala, apparently carried out by the Army, that had reportedly annihilated hundreds of Mayan villages and wiped out nearly 200,000 Indian men, women and children. I sat in a small room in Sacramento and listened to a boy tell me how soldiers had taken his father, forced him and other prisoners to walk on broken glass, put heated iron to their feet and stuck needles under their fingernails. He described how the soldiers mutilated the prisoners, and how they cut pieces from his father’s chest, back and arms before throwing the dying man into a large hole filled with burning trash.

That boy’s testimony, along with the testimony of other survivors, led us to bring a federal suit in 1991 against Hector Gramajo, a Guatemalan general we identified as responsible for many of the atrocities. Gramajo, who had close ties to the United States, was then spending a year on a Mason Fellowship at the John F. Kennedy School of Government at Harvard. In 1995, Judge Douglas Woodlock entered a judgment against Gramajo for $42.5 million dollars on behalf of eight Kanjobal Indians. The judge found that during the 1980s Gramajo supervised Army intelligence, which provided lists of individuals to be eliminated, and was “aware of and supported widespread acts of brutality by personnel under his command resulting in thousands of civilian deaths,” and that he had “devised and directed the implementation of an indiscriminate campaign of terror.”

At the time of the lawsuit we were aware that Gramajo had been trained at the U.S. Army School of the Americas, and that the Guatemalan military in general had been trained, advised and supported by the Pentagon and C.I.A.. What we did not know is what was recently revealed by the U.N.-sponsored Guatemalan truth commission: that the influence of the United States had “a significant bearing” in the genocide against the Mayan Indians. In an exhaustive survey of the violence in four different regions of the country, the commission found that with regard to our plaintiffs, the Mayan Kanjobal in Huehuetenango, the Guatemalan military took actions “with the intention of totally or partially destroying” those communities. As to the role of the United States, the commission found that the government of the United States, through individual officials of various agencies including the CIA, provided direct and indirect support for some illegal state operations, which helped military units engage in torture, kidnappings and executions. Worst of all, the commission made it clear that the United States had knowledge of the genocide as it was happening, and continued nonetheless to support the Guatemalan military.

On both legal and moral grounds, we believe this means that the judgement against Hector Gramajo in the case of the Kanjabol Indians ­which he has refused to pay– is in effect a judgment against the United States government and its officials. We believe it is the responsibility of these officials to compensate the victims of Gramajo’s crimes.

Sadly, the reckoning against Gramajo and his U.S. supporters is only a small part of the work of justice that remains to be done .in Guatemala. The United States has made genocide and torture federal crimes It has furthermore signed the Genocide Convention and the Convention Against Torture, which state that all those complicit in genocide or torture must be punished. Now that there is public evidence that U.S. officials were involved in the atrocities of the Guatemalan genocide, it is time for an investigation and prosecution of everyone complicit in those crimes.

To come to terms with the full scope of the genocide against Guatemala’s Mayan communities, the United States must publicly release all documents pertaining to its role during the years of terror, and must open its records to impartial investigation. As it has done with the prosecution of former Nazis, the United States should set up a special unit in the Justice Department to investigate and prosecute those US officials, from the CIA or other agencies, complicit in acts of torture and genocide in Guatemala. And as the United States has a responsibility to the victims of genocide and torture, it should establish a fund to pay reparations to victims and survivors in Guatemala.

The truth commission in Guatemala has taken a brave and necessary first step to ensure that those responsible for genocide will not escape responsibility. The United States government must step forward now — not only to fulfill its international legal obligations and its moral obligations to the victims, but to send a message that crimes against humanity like those committed against the Maya in Guatemala will never be repeated.

Michael Ratner is a human rights attorney with the Center for Constitutional Rights in NYC and was co-counsel in Xuncax v. Gramajo.